2 Answers
2

If the method causes the async functionality to begin, then I would call it Begin....

If the method causes the async functionality to end, then I would call it End...

If the method should be run before the async functionality starts, then I might call it Pre...

If the method should be run after the async functionality ends, then I might call it Post...

The begin and end options seem to indicate that they cause things to happen with respect to the async function, like turning the key in the ignition, or turning it off again.

The pre and post options seem to indicate that they are detached from the actual async function they surround, like closing the car door before you put your foot on the accelerator, or putting on the handbrake before exiting the car.